effects of upping fuel pressure k jet?

[Preen59]

Ha Golf balls you saved me from saying that!!!!!!!!!!!!!!!!!!!!!
Jmac

And me saying it AGAIN! haha.

[Oneofthegreats]

Judging by what I can sort of decipher from your posts & also agreeing with everyone else.

It would make it much much easier if you make your posts clearer with actual sentences & explaining your problems in point form.

That way some of use can read & interpret your info as best as possible & hopefully give you some sort of direction.

Now if these people are trying & pushing you to install EFI for nearly stock VW Golf. Its because they have not one idea between them about the system!

A good place to start would also be purchasing a book on Bosch K-Jet fuel injection as already advised & learning how the system operates.

After all. How can you start modifying & playing around with things, if you have no clue how it works in the first place?



First & foremost.

If your K-Jet system is 100% & has no problems eg. hard start, faulty accumulator, leaky injectors etc, then I'd start looking at other things. But to start off with

The system "must" be in 100% operating condition


Now! Straight away I'd be checking exactly what your A/F ratio is & just as importantly, your CO%.

In NA (normally aspirated) form I always set my K-Jet cars up with 2.0% CO. This is without any additional loads. Eg. lights on, thermo fans running etc.

Your mixture/airflow rate is all in the design of the air flow sensor bowl. If you've seen enough of them, you'll see there is differences in how they are shaped. This defines how your car adjust's its A/F ratio through out load/air flow requirements,

If your CO% is approx 2.0%, then I'd be looking into your fuel system pressure.

System pressure

68-78psi

Control Pressure

Cold (10°C) approx 15-20psi
Hot approx 49-55psi

If this is right, then you can look into increasing your fuel pressure, or as I've found & used several times over & recommended it to anyone & everyone with VW K-jet cars before increasing fuel pressures -

Install a K-Jet airflap & metering head out of a larger capacity K-Basic car!

I always recommend a setup out of a early 80's Volvo 2.1-2.2L car. The airflap is larger diameter, lifts up more (increasing fuel flow through the metering head plunger slots) & also the metering head flows more fuel to suit the larger capacity engine.

(The VW K-Jet injectors are one of the highest flowing injectors, so there is no need to go in search of better ones.)

This provides very noticeable increases to throttle response, bottom end torque & high rpm fueling. This fueling system will also be able to handle approx 200+hp in FI (forced induction) form, as I've proved with my own install.

But it has to be working 100%!

If tuned right eg. 2.0% CO your fuel consumption shouldn't increase by all that much either.

I've been using this setup for over 14+ years now & have never had a problem with it & still get high 7's-mid 8's litres per 100km. This is even with the K-Jet turbo install!

Just recently I got 440km out of 35L!!!!!. Not bad for a turbo'd car using K-Jet!

Thats 7.95L per 100km!

My K-Jet turbo build for interest sake

http://www.vwwatercooled.org.au/f55/...ild-38095.html

[Preen59]

Read Tim's info he has posted carefully and possibly print it out for your mechanic- He knows his ****.

[Jmac]

Agree and again i say K jet in its day was an awesome set up when it was right. i loved it. Still do, only in the Uk teebag fuel filler necks killed them , they hate water and crap. they also hate lying around, had many 911s out of for a Sunday once in 6mths die. Get the Bosch K jet book, well worthwhile read, also includes L and Digifant FTW.
Jmac

[wes csi]

Im really impressed with u guys i feel your expertise does not match up too your english skills. There i used a full stop happy. Now can u please give me some vw technical advice because i feel that the question was clear enough although gammatically incorrect and yes you are a prick because i think u know nothing about kjet and as of now i am not interested in anything you have too say, if you really want to talk about something speak to your wife, shrink, dog i think your get the point. As for the gents that gave good and serious advise thanks for being genuine about my problem.

[h100vw]

Im really impressed with u guys i feel your expertise does not match up too your english skills. There i used a full stop happy. Now can u please give me some vw technical advice because i feel that the question was clear enough although gammatically incorrect and yes you are a prick because i think u know nothing about kjet and as of now i am not interested in anything you have too say, if you really want to talk about something speak to your wife, shrink, dog i think your get the point. As for the gents that gave good and serious advise thanks for being genuine about my problem.

That's just the right way to go, to get yourself banned mate.

golfworx put up what you need.

The same information is in the Haynes WORKSHOP MANUAL for the MK2, not the new service and repair manual. The manual has a green cover.

"dont think it performs like it should it overfueled with faulty injectors and revved more agressively." What does this mean?

Wade and Preen were trying to make our lives easier by getting you to punctuate your posts. So please read them back to yourself before submitting and maybe run a spell checker too.

Gavin

[Preen59]

Im really impressed with u guys i feel your expertise does not match up too your english skills. There i used a full stop happy. Now can u please give me some vw technical advice because i feel that the question was clear enough although gammatically incorrect and yes you are a prick because i think u know nothing about kjet and as of now i am not interested in anything you have too say, if you really want to talk about something speak to your wife, shrink, dog i think your get the point. As for the gents that gave good and serious advise thanks for being genuine about my problem.

Spitting out jibberish and then getting upset when someone asks you to speak more clearly is not the best way to get help, i find.. You have asked something of us, and in return we have asked something of you. If you don't like give and take, feel free to **** off and find someone in your own country to give you some advice...

But wait, you said they don't know anything? Well there you go. Help us to help you mate and don't get off your bike because you've been (constructively) criticised for a couple of posts, that quite frankly made **** all sense to EVERYONE but you. And this post was only marginally better than your last two, i must say.

Happy to help.

[wes csi]

Ok ok i get it.
This will be my final attempt then i give up.
QUESTION 1
Does upping the fuel pressure on the metering head actually improve performance?

EXPLANATION (For arguements sake i have a bog standard car will upping the fuel pressure improve performance.)

QUESTION 2
If hyperthetically if it does or does not what happens to the fuel or burning of fuel inside the engine when the pressure is pushed up.


ps (please pretty please understand my question this time or all the people ive spoken too in my entire life have actually never understood me.)

[Preen59]

Ok ok i get it.
This will be my final attempt then i give up.
QUESTION 1
Does upping the fuel pressure on the metering head actually improve performance?

EXPLANATION (For arguements sake i have a bog standard car will upping the fuel pressure improve performance.)

QUESTION 2
If hyperthetically if it does or does not what happens to the fuel or burning of fuel inside the engine when the pressure is pushed up.


ps (please pretty please understand my question this time or all the people ive spoken too in my entire life have actually never understood me.)

1. Performance will only be improved if the mixture is lean. So yes, if can improve the performance, but only if the engine is asking for more fuel. Increasing the fuel pressure is like putting bigger jets in your carburettor, think of it that way.

2. If you make the mixture rich, the charge will burn cooler and slower. This reduces the engine's performance and will give you wet or sooty spark plugs, poor economy and it will blow lots of black soot. In extreme cases (way rich) you will wash the bores (with fuel), wreck your rings and fill your sump with fuel, over time.

I hope that's what you were asking..

[h100vw]

1. Performance will only be improved if the mixture is lean. So yes, if can improve the performance, but only if the engine is asking for more fuel. Increasing the fuel pressure is like putting bigger jets in your carburettor, think of it that way.

2. If you make the mixture rich, the charge will burn cooler and slower. This reduces the engine's performance and will give you wet or sooty spark plugs, poor economy and it will blow lots of black soot. In extreme cases (way rich) you will wash the bores (with fuel), wreck your rings and fill your sump with fuel, over time.

I hope that's what you were asking..

In addition to the above, to get the most from the engine it needs the right amount of fuel and air and the spark to be delivered at the right time.

There's many factors that will affect the power produced. This is why electronic ignition and fuel injection have been developed and widely used for many years.

The ability of electronics to deliver the fuel and spark at the right time, is far superior to carbs and distributors with vacuum advance.

Gavin